this is the interesting part of LPS . i have this piece of hammer for around 6 months and they have grow from 11 to 16 heads. mine is a branching hammer type coral.
one of the head will sub divide into 2 smaller head and the 2 smaller head will grow from there . heard that once your ca, alkalinity , phosphate level is in check, naturally they will thrieve. as for mi in my case , it took around 6 months.